Background: Phenobarbital is a long-acting barbiturate,
responsible for many cases of poisoning, from unintentional
overdose or attempted suicide. We report a case of phenobarbital
overdose in a patient with history of depression.
Patients and Methods: A 60 year old woman was admitted to
our Internal Medicine Unit for drowsiness, irritability, difficulties in
the maintenance of an upright position, dysphasia and weakness.
She was suffering from depression and epilepsy and treated with
phenobarbital 150 mg/die.
Results: At the admittance, she had high fever and neck stiffness;
phenobarbital serum levels were 71.2 mcg/ml (3 times u.n.l.);
aminotransferases were 12-17u.n.l. Arterial blood pressure was
80/50 mmHg. An inflammatory meningeal process was excluded
by lumbar puncture; a brain and spinal cord CT scan excluded
spine bone lesions and ischemic stroke. In the suspect of an
overdose, a protocol of urine alkalinization was applied resulting
in a reduction of phenobarbital levels below the therapeutic range
in about 6 days, with state of consciousness, cognitive and
behavioral functions improvement. A rapid normalization in
aminotransferases levels was noted and serology for hepatitis
viruses (HAV, HBV, CMV, EBV, HSV) resulted negative.
Conclusions: In our patient phenobarbital was responsible for
stupor, hypotension, hypertonicity and aminotransferases
elevation, whereas fever was due to a concomitant pulmonary
inflammatory process resolved after antibiotic therapy. Despite the
use of these drugs has been progressively reduced, the number
overdose reports remains still hig